JPH02188070A - Line density converting circuit - Google Patents

Abstract

PURPOSE:To output picture element lines as many as input picture element lines by inserting virtual white picture element line data after an actual final input picture element line when line density conversion is performed by referring to a laser and a following picture element line. CONSTITUTION:When the magnification in a subscanning direction is X1, the final input line and final converted picture element line overlap with each other, so there is no reference line corresponding to the following line when a final input line is regarded as the last line. Here, the final input line is sent to a last picture element line buffer 2 and then an image converting circuit 1 outputs a white mask signal to a signal line 1a to regard the data of a following picture element line buffer 3 as a white picture element signal. This is regarded as a virtual white line corresponding to the following line to convert the image of the final output line. Consequently, the number of input lines is equalized to the number of output lines.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a still image processing device, and more particularly to a line density conversion circuit that refers to image data of a previous line and image data of a subsequent line.

(Prior Art) Conventionally, this type of line density conversion circuit has performed pixel conversion using only input pixel line data.

(Problem to be Solved by the Invention) In the conventional line density conversion circuit as described above, input pixel line data is used to convert both data of the previous line and subsequent line image data for each converted pixel line. Pixel conversion is performed using input pixel data consisting of: Therefore, when performing pixel conversion with a magnification of 1 times the sub-scanning direction, even if you try to obtain the number of output lines equal to the number of input lines, there is no line image data after converting the final output line, so The drawback is that the number of output lines is less than the number of input lines.

An object of the present invention is to eliminate the above drawback by referring to the previous pixel line and the subsequent pixel line and inserting virtual white pixel line data after the actual final input pixel line when performing line density conversion. .

An object of the present invention is to provide a confidentiality conversion circuit configured so that it can output the same number of output pixel lines as the number of input pixel lines during pixel conversion at a magnification of 1 in the sub-scanning direction.

(Means for Solving Problem A) A linear density conversion circuit according to the present invention includes a pixel conversion circuit, a rear pixel line buffer, and a front pixel line buffer.

The pixel conversion circuit inputs the previous line image data and the subsequent line image data, performs image conversion, and outputs the converted image data as well as a white mask signal.

The rear pixel line buffer inputs the reference pixel signal and outputs the rear line image data, and when the white mask signal is received, the image data is used as a white pixel and the line image data is forwarded sequentially.

The previous pixel line buffer is for outputting previous line image data by sequentially inputting line image data.

(Example) Next, one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a linear density conversion circuit according to the present invention. In FIG. 1, 1 is a pixel conversion circuit, 2 is a front pixel line pack 7, and 3 is a rear pixel line buffer.

The pixel conversion circuit 1 inputs the previous line image data and signal on the signal #I2&, and the subsequent line image data on the signal 113a, performs image conversion, outputs the converted image data on the signal line 1h, and outputs the converted image data on the signal line 1h. A white mask signal is output on 1a. The rear pixel line buffer 3 inputs the reference pixel via the signal line 3h, and outputs the rear line image data on the signal 11iI3a. At the same time, the rear pixel line buffer 3 receives the signal l5l.
When a white mask (2) is received from a, a data shift signal is sent on the signal @3c in order to make the image data in the own buffer a white pixel. The line image data is sent sequentially in units of 2 lines.The line image data is inputted by the data shift signal on the signal #l13c from the previous pixel line (in the case of the 2 line), and the previous line image is transferred from the previous pixel line (from the 2 line to the signal line 2a). Data is output.

FIG. 2 is an explanatory diagram showing a procedure for image conversion by the linear density conversion circuit shown in FIG. In FIG. 2, the O mark is a reference pixel, the x mark is a converted pixel, and the 10 mark is a white pixel. In FIG. 2, (1) shows an example of a picture guest reception when the magnification in the sub-scanning direction is not 1x. When the image data of the first line is input to the rear pixel line buffer 3, the data is immediately sent to the previous pixel line buffer 2, and the image data of the next line is input to the rear pixel line buffer 3.

At this point, image conversion starts, and the previous pixel line buffer 2
The data in the subsequent pixel line buffer 3 is referred to as the image data for the previous line, and the data in the subsequent pixel line buffer 3 is referred to as the image data for the subsequent line.

While the converted pixel line is on the previous line and immediately before the next line, image conversion is performed using the previous line and the next line at that time as reference lines. When the position of the converted pixel line reaches the next line, one-pixel conversion is interrupted, the data in the next pixel line buffer 3 is sent to the previous pixel line buffer 2, and the next pixel line buffer 3 receives the image data of the new line. input and image conversion resumes.

In FIG. 2, (11) shows an example of image conversion when the magnification in the sub-scanning direction is 1x.

Next, with reference to FIG. 2(H), the conversion of the final output line after matching the number of input lines and the number of output lines will be described. @2 In (11) in Figure 2, the final input line and the final converted pixel line 7 overlap, so when the final input line is the previous line, there is no reference line corresponding to the subsequent line 1. Therefore, instead of sending the final input line to the previous pixel line buffer 2, the last pixel conversion circuit 1 outputs a white mask signal onto the signal line 1a to make the data in the next pixel line buffer 3 a white pixel signal. This is used as a virtual white line corresponding to the rear line in FIG. 142 (1), and I&end output color line image conversion is performed.

(Effects of the Invention) As explained above, the present invention refers to the previous pixel line and the subsequent pixel line, and inserts virtual white pixel line data after the actual final input pixel line when performing line density conversion. This has the effect that when pixel conversion is performed with the magnification in the sub-scanning direction set to 1, it is possible to output the same number of output pixel lines as the number of input pixel lines.

[Brief explanation of the drawing]

FIG. fa1 is a block diagram showing an embodiment of a linear density conversion circuit according to the present invention. FIG. m2 is an explanatory diagram showing a procedure for performing image conversion by the linear density conversion circuit having the configuration shown in FIG. 1... Pixel conversion circuit 2, e, front pixel line buffer 3... rear pixel line buffer 18, lb, 2a13a, 3h13c, @#@(rib line) Fig. 2 00. Signal line patent applicant Hisashi Inoro, agent for NEC Corporation, patent attorney

Claims (1)

[Claims] A pixel conversion circuit inputs the previous line image data and the subsequent line image data, performs both conversions, outputs the converted image data and outputs a white mask signal, and inputs a reference pixel signal and converts the latter line image data. and a subsequent pixel line buffer for sequentially feeding the line image data with the image data as a white pixel when receiving the white mask signal, and a line buffer for outputting the previous line image data by sequentially inputting the line image data. 1. A line density conversion circuit comprising a previous pixel line buffer.